摘要:
Systems and methods for scheduling instructions using pre-decode data corresponding to each instruction. In one embodiment, a multi-core processor includes a scheduling unit in each core for selecting instructions from two or more threads each scheduling cycle for execution on that particular core. As threads are scheduled for execution on the core, instructions from the threads are fetched into a buffer without being decoded. The pre-decode data is determined by a compiler and is extracted by the scheduling unit during runtime and used to control selection of threads for execution. The pre-decode data may specify a number of scheduling cycles to wait before scheduling the instruction. The pre-decode data may also specify a scheduling priority for the instruction. Once the scheduling unit selects an instruction to issue for execution, a decode unit fully decodes the instruction.
摘要:
Systems and methods for scheduling instructions using pre-decode data corresponding to each instruction. In one embodiment, a multi-core processor includes a scheduling unit in each core for selecting instructions from two or more threads each scheduling cycle for execution on that particular core. As threads are scheduled for execution on the core, instructions from the threads are fetched into a buffer without being decoded. The pre-decode data is determined by a compiler and is extracted by the scheduling unit during runtime and used to control selection of threads for execution. The pre-decode data may specify a number of scheduling cycles to wait before scheduling the instruction. The pre-decode data may also specify a scheduling priority for the instruction. Once the scheduling unit selects an instruction to issue for execution, a decode unit fully decodes the instruction.
摘要:
One embodiment of the present invention sets forth a technique for speculatively issuing instructions to allow a processing pipeline to continue to process some instructions during rollback of other instructions. A scheduler circuit issues instructions for execution assuming that, several cycles later, when the instructions reach multithreaded execution units, that dependencies between the instructions will be resolved, resources will be available, operand data will be available, and other conditions will not prevent execution of the instructions. When a rollback condition exists at the point of execution for an instruction for a particular thread group, the instruction is not dispatched to the multithreaded execution units. However, other instructions issued by the scheduler circuit for execution by different thread groups, and for which a rollback condition does not exist, are executed by the multithreaded execution units. The instruction incurring the rollback condition is reissued after the rollback condition no longer exists.
摘要:
One embodiment of the present invention sets forth a technique for speculatively issuing instructions to allow a processing pipeline to continue to process some instructions during rollback of other instructions. A scheduler circuit issues instructions for execution assuming that, several cycles later, when the instructions reach multithreaded execution units, that dependencies between the instructions will be resolved, resources will be available, operand data will be available, and other conditions will not prevent execution of the instructions. When a rollback condition exists at the point of execution for an instruction for a particular thread group, the instruction is not dispatched to the multithreaded execution units. However, other instructions issued by the scheduler circuit for execution by different thread groups, and for which a rollback condition does not exist, are executed by the multithreaded execution units. The instruction incurring the rollback condition is reissued after the rollback condition no longer exists.
摘要:
A parallel thread processor executes thread groups belonging to multiple cooperative thread arrays (CTAs). At each cycle of the parallel thread processor, an instruction scheduler selects a thread group to be issued for execution during a subsequent cycle. The instruction scheduler selects a thread group to issue for execution by (i) identifying a pool of available thread groups, (ii) identifying a CTA that has the greatest seniority value, and (iii) selecting the thread group that has the greatest credit value from within the CTA with the greatest seniority value.
摘要:
A parallel thread processor executes thread groups belonging to multiple cooperative thread arrays (CTAs). At each cycle of the parallel thread processor, an instruction scheduler selects a thread group to be issued for execution during a subsequent cycle. The instruction scheduler selects a thread group to issue for execution by (i) identifying a pool of available thread groups, (ii) identifying a CTA that has the greatest seniority value, and (iii) selecting the thread group that has the greatest credit value from within the CTA with the greatest seniority value.
摘要:
A computing device detects divergences between threads in a thread group executing on a parallel processing unit. The computing device includes an address divergence unit that identifies a subset of non-divergent threads included in the thread group. The address divergence unit stores instructions related to the subset of non-divergent threads in a multi-issue queue. The address divergence unit causes the instructions related to the subset of non-divergent threads to be retrieved from the multi-issue queue when the parallel processing unit is available. The address divergence unit causes the subset of non-divergent threads to be issued for execution on the parallel processing unit. The address divergence unit repeats the identifying, storing, and causing steps for the remaining threads in the thread group that are not included in the subset of non-divergent threads.
摘要:
An address divergence unit detects divergence between threads in a thread group and then separates those threads into a subset of non-divergent threads and a subset of divergent threads. In one embodiment, the address divergence unit causes instructions associated with the subset of non-divergent threads to be issued for execution on a parallel processing unit, while causing the instructions associated with the subset of divergent threads to be re-fetched and re-issued for execution.
摘要:
States that are used in configuring a processing pipeline are passed down through a separate pipeline in parallel with the data transmitted down through the processing pipeline. With this separate pipeline, the states for configuring any one stage of the processing pipeline are continuously available in the corresponding stage of the state pipeline, and new states for configuring the processing pipeline can be transmitted down the state pipeline without flushing the processing pipeline. The processing pipeline and the separate pipeline for the states can be divided into multiple sections so that the width of the separate pipeline for the states can be reduced.
摘要:
One embodiment of the present invention sets forth a technique for improving graphics rendering efficiency by processing pixels in a compressed format whenever possible within a multi-sampling graphics pipeline. Each geometric primitive is rasterized into fragments, corresponding to screen space pixels covered at least partially by the geometric primitive. Fragment coverage represents the pixel area covered by the geometric primitive and determines the weighted contribution of a fragment color to the corresponding screen space pixel. Samples associated with a given fragment are called sibling samples and have the same color value. The property of sibling samples having the same color value is exploited to compress and process multiple samples, thereby reducing the size of the associated logic and the amount of data written to and read from the frame buffer.